The first has been the 'commodification' of the dog, shaping it to conform to human expectations of personality and behaviour. The second has been the broadening of the concept of the family and the home to include dogs-as-dogs within everyday routines and practices. There are a vast range of commodity forms available to transform a pet dog into an ideal companion. The list of goods, services and places available is enormous: from dog perfumes, couture, furniture and housing, to dog groomers, therapists, trainers and caretakers, dog cafes, spas, parks and beaches, and dog hotels, airlines and cemeteries. While dog training as an organized activity can be traced back to the 18th century, in the last decades of the 20th century it became a high profile issue as many normal dog behaviors such as barking, jumping up, digging, rolling in dung, fighting, and urine marking[further explanation needed] became increasingly incompatible with the new role of a pet dog. Dog training books, classes and television programs proliferated as the process of commodifying the pet dog continued. An Australian Cattle Dog in reindeer antlers sits on Santa's lap A pet dog taking part in Christmas traditions The majority of contemporary people with dogs describe their pet as part of the family, although some ambivalence about the relationship is evident in the popular reconceptualization of the dog–human family as a pack. A dominance model of dog–human relationships has been promoted by some dog trainers, such as on the television program Dog Whisperer. Breeds are usually categorized by the functional type from which the breed was developed. Breeds are usually categorized by the functional type from which the breed was developed. As such, dogs are the only animal with such a wide variation in appearance without speciation, "from the Chihuahua to the Great Dane". The following list uses a wide interpretation of "breed". It was not until 1970 that The Kennel Club in the UK recognised the American Cocker Spaniel as being separate from the English type.
Matings between hairless AHTs will produce completely hairless litters. Some dogs, such as the Löwchen, have an uncertain origin and are listed under several countries. Yet, although several programs are undergoing to promote pet adoption, less than a fifth of the owned dogs come from a shelter..
The American Hairless Terrier does not have dental issues (absent premolars) or other characteristics associated with the dominant hairless gene. The early ancestors of this breed came from England, where until the first part of the 19th century, the Bulldog was bred in England. From the 1980s, there have been changes in the role of the pet dog, such as the increased role of dogs in the emotional support of their human guardians. People and dogs have become increasingly integrated and implicated in each other's lives, to the point where pet dogs actively shape the way a family and home are experienced. There have been two major trends in the changing status of pet dogs. There does not seem to be any gender preference among dogs as pets, as the statistical data reveal an equal number of female and male dog pets. In 2013, the cocker spaniel ranked 29th the American Kennel Club registration statistics of historical comparisons and notable trends. It is important to note that many modern American Bulldogs are a combination of the two types usually termed "hybrid." In general, American Bulldogs weigh between 27 to 54 kg (60 to 120 lb) and are 52 to 70 cm (20 to 28 in) at the withers, but have been known to greatly exceed these dimensions, especially in the "out of standard," nonworking stock. In 2013, the cocker spaniel ranked 29th the American Kennel Club registration statistics of historical comparisons and notable trends. As such, dogs are the only animal with such a wide variation in appearance without speciation, "from the Chihuahua to the Great Dane". The following list uses a wide interpretation of "breed". By the 1920s the English and American varieties of Cocker had become noticeably different and in 1946 the AKC recognised the English type as a separate breed.